An air conditioning device such as an office-building use multi-split type air conditioner is such that one outdoor unit (heat source machine), disposed on an office-building rooftop or the like, and indoor units, disposed one each in a multiple of spaces subjected to air conditioning inside a building, are connected, and the temperature of each space subjected to air conditioning is regulated.
As an existing air conditioning device, there is a device such that cooling or heating of a space subjected to air conditioning is carried out by a refrigerant such as a hydrofluorocarbon (HFC) being caused to circulate between an outdoor unit and an indoor unit. The device is such that, when cooling, a refrigerant cooled in the outdoor unit absorbs heat from the air in a space subjected to air conditioning in the indoor unit, and when heating, a refrigerant heated in the outdoor unit releases heat into the air in a space subjected to air conditioning from the indoor unit.
However, a device wherein a refrigerant such as an HFC circulates as far as an indoor unit has a problem in that the refrigerant leaks inside a space subjected to air conditioning. In order to resolve this kind of problem, an air conditioning device wherein a relay unit is provided between an outdoor unit and an indoor unit, a refrigerant is caused to circulate from the outdoor unit as far as the relay unit, and a heating medium such as water is caused to circulate from the relay unit to the indoor unit, has been proposed in, for example, Patent Document 1.
An inter-heating medium heat exchanger, which causes an exchange of heat between the refrigerant and heating medium to be carried out, and a heating medium channel switching device are included in the relay unit of the existing air conditioning device. A heating-use heating medium heated in the inter-heating medium heat exchanger is conveyed to an indoor unit that carries out a heating operation, and a cooling-use heating medium cooled in the inter-heating medium heat exchanger is conveyed to an indoor unit that carries out a cooling operation. The heating-use heating medium or cooling-use heating medium carries out an exchange of heat with the air in a space subjected to air conditioning in the indoor unit, thereby realizing a heating operation or cooling operation.
Also, a composite valve including a first valve chamber that houses a body of a mixing/switching valve, a second valve chamber that houses a body of a flow control valve, and a channel that causes the first valve chamber and second valve chamber to communicate, has been proposed in Patent Document 2 as a composite valve such that manufacturing costs can be restricted, and for which no plumbing is necessary even when a multiple of the valve are disposed.